Increase coverage (#218)

* Monkeypatch fetch user and use pytest.tempdir

* Cover spotify_tools.grab_album()

* Cover avconv conversion

* Cover grab_single()

* Reduce code repetition

* Move grab_playlist() to spotify_tools.py

* Move Spotify specific functions to spotify_tools.py

* Refactoring

* Return track list from write_tracks()

* Fix tests

* Cover more cases in generate_youtube_url()

* Test for unavailable audio streams

* Test for filename without spaces

* handle.py 100% coverage

* Improve config tests

* Speed up tests

* Install avconv and libfdk-aac

* Some cleaning

* FFmpeg with libfdk-aac, libopus

* Some refactoring

* Convert tmpdir to string

* Cover YouTube title when downloading from list

* Explicitly cover some internals.py functions

test/test_dry_run.py

@@ -0,0 +1,18 @@
+from core import const
+
+import spotdl
+import loader
+import os
+
+loader.load_defaults()
+
+
+def test_dry_download_list(tmpdir):
+    song = 'http://open.spotify.com/track/0JlS7BXXD07hRmevDnbPDU'
+    const.args.folder = str(tmpdir)
+    const.args.dry_run = True
+    file_path = os.path.join(const.args.folder, 'test_list.txt')
+    with open(file_path, 'w') as tin:
+        tin.write(song)
+    downloaded_song, *_ = spotdl.download_list(file_path)
+    assert downloaded_song == song